The household forms an important category in social science research. It is used to collect data, to classify it and to represent the results. However, what seems to be a simple listing of facts becomes less clear when a basic question is raised: What is a household? Is it a family living under one roof? Is a roof limited to a house, or does a flat already constitute a household? Do members of a household have to be officially related, meaning married, adopted etc., or even related by blood? And how do households and definitions of households differ over time and space? Some definitions like the United Nations’s dwelling concept, for example, sound pragmatic with little regard to the social relationships of the actual human beings living in a household. However, there are indeed power relations within a household (e.g. between parents and children). Social scientists also observed these everyday asymmetries and therefore constructed a hierarchy in social classifications when they placed the household in a specific class according to the ›Head of Household‹ or the ›Household Reference Person‹, the ›Chief Wage Earner‹, the ›Householder‹ etc. The different designations of the reference person indicate that it is not an easy task to name this person or to define this person without a normative bias. By taking the example of Great Britain, this article demonstrates that the definition of the ›Head of Household‹ was a normative category rather than a descriptive one, meaning that it was less able to facilitate analysis of social reality and that it fortified a normative view with the help of statistics. While feminists and other historical actors in different states, for example the U.S., already criticised the normative bias of the definition in the 1960s and 1970s, a different question seems to be of equal or even greater importance to the historian: How, when and why did different nations and professions decide to drop the normative in favour of a descriptive definition of the ›Head of Household‹? This leads to a more general question: How did administrators, statisticians and other survey researchers deal with the aim of long-term stability of statistical categories for the sake of comparability, e.g. in a national census, on the one hand, and with adaption to societal change on the other hand? In taking the example of the United Kingdom, the following story combines aspects of a history of knowledge with administrative history.